Base sheet for self-adhering membranes and selvage roll for such membranes

ABSTRACT

A base sheet for a roof includes a laminate of a metal layer, a core layer and a plastic layer with the metal layer being on one side of the core layer and the plastic layer being on an opposite side. The core layer is made of a polyester non-woven fabric, a polypropylene non-woven fabric, a polyethylene non-woven fabric or a woven or non-woven fiberglass; the plastic is made of polyester, polypropylene, polyethylene or a spun bonded olefin; and the metal of the metal layer is aluminum. A self-adhering membrane is adhered to the laminate. Preferably, the self-adhering membrane includes a mineral surfaced area and a plurality of non-mineral surfaced areas forming selvage strips. The base sheet may be attached to an insulating board in situ or may be attached to the insulating board in a factory. In the latter case, the base sheet has at least two overhanging sides.

CROSS REFERENCES TO RELATED APPLICATION

[0001] This application is based on Provisional Application Ser. No.60/477,491, filed Jun. 9, 2003 and entitled “IMPROVED BASE SHEET,”Provisional Application Ser. No. 60/482,213, filed Jun. 24, 2003 andentitled “IMPROVED BASE SHEET” and Provisional Application Ser. No.60/487,713, filed Jul. 16, 2003 and entitled “SELVAGE ROLL.” The entiredisclosure of each of the provisional applications is incorporated byreference herein.

BACKGROUND OF THE INVENTION

[0002] The present invention relates generally to roofs and, moreparticularly, to a roof having an improved base sheet for self-adheringmembranes and a selvage roll for such membranes.

[0003] Conventionally, roof membranes are applied to base sheets using avariety of methods.

[0004] One method of application is referred to as “torching,” in whichthe back surfaces of the rolls are heated. Heating of the bitumen-basedroofing membranes is typically carried out by use of propane gas burnersor torches. When the flame, which has a typical temperature of 1,000 to1,300 degrees Celsius is directed toward the bottom surface of thesheet, APP compound from the bottom surface reaches a molten state andstarts to flow onto the substrate and then cools to form a waterproofingbond. It is obvious that torching is dangerous considering the risk offire caused by the utilization of a torch and other similar equipment.

[0005] Another method is applying hot asphalt to the base sheet by atechnique known as “hot mopping.” Hot mopping, while reducing the riskof fire versus torch application, still poses a substantial risk offire.

[0006] A further method, which essentially reduces the risk of fire tothe base sheet and underlying structure is the use of self-adheringmembranes. A self-adhering membrane is a membrane that can adhere to anunderlying layer and to an overlying layer at overlaps without the useof an additional adhesive. The undersurface of a self-adhering membraneis protected by a release paper or film, which prevents the membranefrom bonding to itself during shipping and handling.

[0007] Self-adhering membranes are usually formed into rolls for use ininstalling the membrane on a roof. Currently, self-adhering membraneshave a top selvage edge and one selvage end lap. A selvage edge is anedge or edging that differs from the main part of (1) a fabric, or (2)granule-surfaced roll roofing material. More specifically, in the caseof self-adhering modified bitumen membranes, the mineral surfacing isomitted over a small portion of the longitudinal edge of a sheet inorder to obtain better adhesion of the lapped sheet surface with anoverlying sheet. Ideally, the two sheets should be joined with the useof an adhesive selvage edge. Unfortunately, many times a roll must becut short of the selvage end lap due to the dimensions of the roof. Whenthis happens, the selvage end lap gets cut off and the material must nowadhere to a mineral-surfaced edge. However, the material does not adherewell to such an edge.

SUMMARY OF THE INVENTION

[0008] The present invention provides a base sheet which may be usedwith either conventional methods of applying overlying layers or withself adhering membranes and, in either case, provides superior fireresistance.

[0009] The present invention also provides a selvage roll forself-adhering membranes, particularly self-adhering modified bitumenmembranes, which solves the end lap problem.

[0010] In the case of a built-up roof, the metal layer serves as a firebarrier to prevent bitumen entering the underlying building and fuelinga fire. Additionally, the metal layer acts as a barrier for preventingany bitumen (or other material) applied during installation frompenetrating the deck and into the interior of the underlying building.

[0011] Whatever the type of roof assembly, the metal layer enables theroof assembly to resist an interior fire.

[0012] The provision of a plurality of selvage portions enables allowssizing of a roll to required dimensions while still providing a selvageend lap to enable the roll to be attached in a mineral free portion toan overlying roll.

[0013] Other features and advantages of the present invention willbecome apparent from the following description of the invention whichrefers to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a sectional view of a prior art roof;

[0015]FIG. 2 is a sectional view of a roof illustrating certain featuresof the present invention;

[0016]FIG. 3 is a sectional view of a roof having a self-adheringmembrane illustrating certain features of the present invention;

[0017]FIGS. 4 and 5 are a perspective view and an elevation view,respectively, illustrating certain features of the present inventions,of a factory installed combined insulating board and base sheet whereinthe base sheet overhangs the insulating board on at least two sides;

[0018]FIGS. 6 and 7 are a plan view and a perspective view,respectively, of a base sheet having selvages illustrating certainfeatures of the present invention; and

[0019]FIG. 8 is a plan view of an alternative embodiment of a base sheethaving selvages illustrating certain features of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0020] Although the present invention is applicable to any type of roof,it has particular applicability in connection with its use in built-up,single ply and self-adhering membrane type roofs.

[0021] Built-up roofs are formed of alternate layers of bituminousmaterial and felt which are assembled or “built-up” in the field. Thealternate layers of bituminous material and felt are assembled onto anoverlay which overlies an insulation layer. The insulation layer andoverlay are attached to a roof deck which typically is made of metal,wood, concrete gypsum or any other conventional deck material. The term“built-up roof composite” as used herein means any one of a plurality ofdifferent conventional built-up roof composites used on the top ofoverlays, such as the built-up roof composite described herein, as wellas others, such as EPDM, PVC, modified bitumen, coal tar and Hypolon.

[0022] An alternative structure to the built-up roof is a weatherresistant elasto-plastic membrane which may comprise, for examplereinforced polyvinyl floride, butyl rubber, vinylidene chlorides andfluorides, polyesters, polyvinyl chloride, neoprene, chlorosulfonatedpolyethylene, polysulfides, polyurethanes, polyepoxies, acrylates, andother materials having suitable mechanical strength and weatherdurability. Such structures are generally designated “single-ply roofs”because a single thickness of the weather-resistant membrane isgenerally sufficient, as compared with the plurality of layers ofroofing felt generally required for built-up roofs. In addition to themembrane, a layer of insulating material is also generally providedbetween the membrane and the roof deck of the structure in single-plyroofs.

[0023] A self-adhering membrane type roof is formed from two or moremembranes that can adhere to an underlying layer and to an overlyinglayer at overlaps without the use of an additional adhesive. Theundersurface of a self-adhering membrane is protected by a release paperor film, which prevents the membrane from bonding to itself duringshipping and handling.

[0024] The term “roof covering” as used herein means either a built-uproof composite, a single ply or a self-adhering membrane.

[0025] Referring now to the drawings and, particularly, to FIG. 1, thereis shown an embodiment of a roof 20 illustrating certain features of theinvention described in U.S. Pat. No. 6,108,993, the entire disclosure ofwhich is incorporated by reference herein. The roof 20 includes a deck21 which, as shown in FIG. 1, is made of metal but which may be made ofwood, concrete, gypsum or any other conventional deck material.Overlying the deck 21 is an insulation layer 22 which typically is madeof any conventional roof insulating material, such as isocyanurate,polyurethane, wood fiber, fiber glass, perlite or any other lightweightinsulating material. A base sheet 23 comprising a laminate of metal 24and fabric 26 overlies the insulation layer 22. Preferably, the metal 24is aluminum and may be 2 mils thick and the fabric 26 is a non-wovenpolyester having a weight ranging from 4 to 14 ounces per square yard. Apolyester sheet having satisfactory properties is one made by theHoechst Celanese Company, New Jersey and sold under the trade name ofTrivera®.

[0026] The base sheet 23 and the insulating layer 22 are attached to thedeck 21 by suitable mechanical fasteners 27, such as screws or nails,which are inserted through respective metal plates (not shown). Over thebase sheet 23 a conventional roof covering 28 which may be either abuilt-up roof composite or a single ply membrane is formed.

[0027] In accordance, with the present invention, referring to FIG. 2,there is shown a roof 30 in which the base sheet 23 of FIG. 1 isreplaced with a base sheet 32. The base sheet 32 has a plastic film 34laminated to one side of a core layer 36 and a metal foil 38 laminatedto the opposite side.

[0028] The plastic film 34 may be composed of any plastic, such aspolyester, polypropylene, polyethylene or a spun bonded olefin, such asTyvek spun bonded olefin.

[0029] The core layer 36 may be composed of any non-woven fabric, suchas polyester non-woven fabric polypropylene non-woven fabric,polyethylene non-woven fabric or a woven or non-woven fiberglass.

[0030] The metal foil 38 may be made from any metal, but preferably ismade of aluminum.

[0031] The base sheet may be used with either the plastic side, as shownin FIG. 2, up or the metal side 38 up. In either case, a self-adheringmembrane adheres to the base sheet in a superior manner.

[0032] Typically, as discussed above, built-up roof composites areformed of alternate layers of bituminous material and felt. The feltsmay be fiberglass or may be organic felt, such as asphalt saturated feltor, as disclosed in U.S. Pat. Nos. 4,521,478, 4,599,258 and 4,837,095,the entire disclosures of which are incorporated by reference, thebuilt-up roof composite 27 may be formed of alternate layers of anon-woven polyester and bituminous material. Typically, the bituminousmaterial is usually of coal tar or asphalt origin and is applied byhot-mopping. The metal layer 24 acts as a barrier to prevent thebituminous material from penetrating down to the underlying insulationlayer 22.

[0033] One of the problems with built-up roofs employing bituminousmaterials is that when there is an internal fire in the building, thetemperatures can be such as to cause the bituminous material to liquifyand penetrate through the deck into the interior, thereby feeding thefire and causing greater fire damage, as well as greater hazard to firepersonnel involved in fighting the fire. Accordingly, it is necessary toprovide a barrier to such bituminous liquid from entering the building.The metal foil provides such a barrier. Further, the fire resistance ofthe metal foil also allows the self-adhering roof membrane to pass acalorimeter fire test. This test measures a roof assembly's capabilitiesto resist an interior building fire.

[0034] The laminate base sheet 32 of the present invention is generallyapplied in discontinuous units such that seams are formed which normallywould allow molten material to flow into the interior of a building.However, it has been found that the seams at the high temperaturesencountered in a building fire cause melting of the overlying polyester,which then enters the seam forming a fluid type seal between adjacentmetal layers 38. This seal prevents any liquid bituminous material frompassing through to any of the underlying layers.

[0035] When the roof covering 28 is a single ply membrane, such membranepreferably comprises an elasto/polymeric material. Without limitation onthe generality of useful materials, the membrane may be formed ofethylene propylene diene monomer (EPDM), modified bitumen (MB),reinforced modified bitumen (MB/R), polychloroprene or neoprene (NEO),polyvinyl chloride (PVC), chlorinated polyethylene (CPE),polyisobutylene (PIB), or ethylene-copolymer-bitumen and anthracitemicrodust (ECB). The adhesive is chosen for its compatibility with thematerial comprising the membrane.

[0036] When the roof covering 28 is formed from self-adhering membranes,such as the self-adhering membranes 40 and 42 (FIG. 3), anyself-adhering membrane may be used such as, self-adhering modifiedbitumen, SBS modified bitumen, APP modified bitumen, etc.

[0037] To install the roof 30, the insulation layer 22 is first laidover the deck 21. Typically the insulation layer 22 is laid over thedeck as a plurality of individual boards. Then, the base sheet 32, whichtypically is supplied from rolls approximately 40″ in width, is laid onthe roof in strips of 40″ width with overlapping seams. The base sheet32 and the insulation layer 22 are then attached to the deck by aplurality of mechanical fasteners 27 which may be screws, nails or,depending upon the deck, toggle bolts, or any other conventionalmechanical fastener, and which are typically inserted through respectivemetal plates (not shown).

[0038] As an alternative to applying the base sheet in situ on theinsulating layer in discontinuous units, the base sheet may be attachedto the insulating layer in a factory. In this case, as shown in FIGS. 4and 5, a base sheet 41 is laminated to a roofing insulation board 43 ofany size. The base sheet 41 is laminated to the insulation board such asto have at least two sides 41 a and 41 b overhang the board with theother sides cut even to the insulating board. Thus, when the boards 43are applied to a roof deck, the base sheet 41 will lap over thepreceding side. The advantages are:

[0039] 1. The base sheet 41 prevents gassing of the insulating board 43when using urethane, isocyanurate or any foam that utilizes gas in thecell. It is well known in the industry that isocyanurate insulationreleases gas from the topside when hot coal tar or hot asphalt isapplied. This gassing causes blistering and delamination of the roofingmembrane. Thus, in installation, the base sheet 41 eliminates the costof the labor and cost of the board overlay which is recommended by NRCA.

[0040] 2. The installing of the base sheet 41 over the insulation boards43 prevents hot molten tar or asphalt flowing between the joints of theinsulation board 43, thereby protecting occupants from serious burns. Inthe case of new construction, it prevents inside workers from beingburned by dripping hot tar or asphalt.

[0041] 3. The base sheet 41, because of the tear resistance of spun bondplastic, enables the insulation board 43 to be secured to the deckutilizing 50% less fasteners then insulating boards void of the basesheet 41. For example, if insulation boards void of the base sheet 41were installed, approximately 36 fasteners would be utilized per 100 sq.ft. to obtain a 90 PSI rating. This wind lift rating is required to bein compliance with all building codes in the United States. Thisreduction in fasteners means less holes in the deck, 50% less fastenersplus 50% less labor for the installation.

[0042] 4. Insulation boards 43 for roofing tend to be brittle. Thelamination of the base sheet 41 to the board 43 reduces the breakageduring shipping and installation resulting in lower costs.

[0043] 5. The base sheet 41 adds dimensional strength to the insulationboard 43. It is well known in the industry that roofing insulation,especially foam type insulation lacks dimensional stability.

[0044] 6. When attaching fasteners through insulation, it is necessarythat all fasteners are installed at the top of metal decking, i.e., inorder to pass Factory Mutual or Global or UL uplift regulations and tocomply with test listings, all fasteners must be at the top of metaldecking. When using a roll consisting of the base sheet, it is verydifficult to locate the top of a corrugated steel decking. Using thecomposite base sheet/insulating board eliminates this problem.

[0045] 7. When the base sheet 41 is laminated to the insulation 43 atthe factory, the task of installation is made easier as the individualboards are laid individually and fastened. In contrast, in the looselaid method, the wind is a negative factor, blowing unfastenedinsulation and causing work stoppage and damage to insulation boards.

[0046] 8. The aluminum of the base sheet 41 acts as a vapor retarder,preventing interior moisture in the form of vapor, from entering underand into the roof membrane which can cause blistering.

[0047] 9. The overlapping of the joints of adjacent boards 43 by theoverhangs 41 a and 41 b, prevents asphalt from flowing through thejoints and into the building feeding the fire from within.

[0048] 10. The two sides that overlap cover the seams in the insulationsaving time and labor by not having to tape the seams in the insulation.

[0049] The base sheet 41 may be the base sheet 32 described above or itmay be the composite polyester/aluminum base sheet described in U.S.Pat. No. 5,884,446 and U.S. Pat. No. 6,108,993, the entire disclosuresof which are incorporated herein by reference. In either case, the basesheet may be attached to the insulation board 43 with the aluminum sideup or down.

[0050] After application of the insulation layer and the base sheet, theroof covering 28 is applied. In the case where the roof covering 28 is abuilt-up roof composite, the built-up roof composite is formed byhot-mopping alternating layers of a hot bituminous material, such as hotasphalt, onto the base sheet 32 with intervening layers of a felt whichmay be a non-woven polyester or any other conventional felt material.

[0051] In the case where the roof covering 28 is a single ply membrane,the single ply membrane is applied to the base sheet 32 by a suitableadhesive. In the case where the roof cover is formed from self-adheringmembranes 40 and 42 (FIG. 3) the self-adhering membrane 40 is attachedto the base sheet using the adhesive backing of the self-adheringmembrane 40. Thereafter one or more additional membranes 42 are appliedwith the adhesive backing of an overlying membrane enabling thatmembrane to be attached to the membrane below it.

[0052] Preferably, each roll 44 of self-adhering membrane (40, 42) isformed as shown in FIGS. 6 and 7, such as to include a mineral surfacedarea 46 on a substrate 48 having a plurality of selvage strips 50 formedalong the roll. The width of each selvage strip may be 4 to 8 inches andthey may be two or three feet apart. It should be recognized that thesedimensions are only exemplary, and the width of the selvage strips 50and their spacing may have any dimensions suitable for the roll's use.Further, the selvage strips 50 may be formed transversely, as shown inFIGS. 6 and 7, or selvage strips 52 may be formed longitudinally, asshown in FIG. 8.

[0053] Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It ispreferred, therefore, that the present invention be limited not by thespecific disclosure herein, but only by the appended claims.

What is claimed is:
 1. A base sheet for a roof comprising a laminate ofa metal layer, a core layer and a plastic layer with the metal layerbeing on one side of the core layer and the plastic layer being on anopposite side.
 2. The base sheet of claim 1, wherein the core layer ismade of a polyester non-woven fabric, a polypropylene non-woven fabric,a polyethylene non-woven fabric or a woven or non-woven fiberglass. 3.The base sheet of claim 1, wherein the core layer is made of a fabric.4. The base sheet of claim 3, wherein the fabric is a polyesternon-woven fabric, a polypropylene non-woven fabric, or polyethylenenon-woven fabric.
 5. The base sheet of claim 1, wherein said plastic ismade of polyester, polypropylene, polyethylene or a spun bonded olefin.6. The base sheet of claim 1, wherein the metal of said metal layer isaluminum.
 7. The base sheet of claim 1, wherein the metal of said metallayer is aluminum, the core layer is made of non-woven polyester and theplastic is a polyester.
 8. A roll of roofing material comprising aself-adhering membrane having a mineral surfaced area and a plurality ofnon-mineral surfaced areas forming selvage strips.
 9. The roll ofroofing material according to claim 8, wherein the self-adheringmembrane comprises a self-adhering modified bitumen, a SBS modifiedbitumen, or an APP modified bitumen.
 10. The roll of roofing materialaccording to claim 8, wherein the selvage strips are formed transverselyalong the membrane.
 11. The roll of roofing material according to claim8, wherein the selvage strips are formed longitudinally along themembrane.
 12. A roof comprising: a deck; and a laminate of a metallayer, a fabric layer and a plastic layer overlying said deck with themetal layer being on one side of the fabric layer and the plastic layerbeing on an opposite side attached to the deck; and a roof covering overthe laminate.
 13. The roof of claim 12, wherein the core layer is madeof a polyester non-woven fabric, a polypropylene non-woven fabric, apolyethylene non-woven fabric or a woven or non-woven fiberglass. 14.The roof of claim 12, wherein said plastic is made of polyester,polypropylene, polyethylene or a spun bonded olefin.
 15. The roof ofclaim 12, wherein the metal of said metal layer is aluminum.
 16. Theroof of claim 12, wherein the core layer is made of a fabric.
 17. Theroof of claim 16, wherein the fabric is a polyester non-woven fabric, apolypropylene non-woven fabric, or a polyethylene non-woven fabric. 18.The roof of claim 12, wherein the metal of said metal layer is aluminum,the core layer is made of non-woven polyester and the plastic is apolyester.
 19. The roof of claim 18, wherein the roof covering is abuilt-up roof composite.
 20. The roof of claim 18, wherein the roofcovering is a single-ply membrane.
 21. The roof of any one of claims12-18, wherein the roof covering is a self-adhering membrane.
 22. Theroof of claim 21, wherein the self-adhering membrane comprises a mineralsurfaced area and a plurality of non-mineral surfaced areas formingselvage strips.
 23. The roof of claim 22, wherein the membrane comprisesa modified bitumen, a SBS modified bitumen, or an APP modified bitumen.24. The roof of claim 23, wherein the selvage strips are formedtransversely along the membrane.
 25. The roof of claim 23, wherein theselvage strips are formed longitudinally along the membrane.
 26. Amethod of forming a roof on a deck comprising: placing an insulatinglayer over said deck; placing a laminate of a metal layer, a core layerand a plastic layer with the metal layer being on one side of the corelayer and the plastic layer being on an opposite side on the insulatinglayer; and adhering a self-adhering membrane to the laminate.
 27. Themethod of claim 26, wherein the laminate is placed on the roof deck suchthat the metal layer faces the deck and wherein the self-adheringmembrane is adhered to the plastic layer.
 28. The method of claim 26,wherein the laminate is placed on the roof deck such that the plasticlayer faces the deck and wherein the self-adhering membrane is adheredto the metal layer.
 29. The method of claims 27 or 28, wherein the corelayer is made of a polyester non-woven fabric, a polypropylene non-wovenfabric, a polyethylene non-woven fabric or a woven or non-wovenfiberglass.
 30. The method of claim 29, wherein said plastic is made ofpolyester, polypropylene, polyethylene or a spun bonded olefin.
 31. Themethod of claim 29, wherein the metal of said metal layer is aluminum.32. The method of claim 29, wherein the core layer is made of a fabric.33. The method of claim 32, wherein the fabric is a polyester non-wovenfabric, a polypropylene non-woven fabric, or a polyethylene non-wovenfabric.
 34. The method of claim 29, wherein the metal of said metallayer is aluminum, the core layer is made of non-woven polyester and theplastic is a polyester.
 35. The method of claim 34, wherein theself-adhering membrane comprises a mineral surfaced area and a pluralityof non-mineral surfaced areas forming selvage strips.
 36. The method ofclaim 35, wherein the membrane comprises a modified bitumen, a SBSmodified bitumen, or an APP modified bitumen.
 37. The method of claim36, wherein the selvage strips are formed transversely along themembrane.
 38. The method of claim 36, wherein the selvage strips areformed longitudinally along the
 39. The method of claims 27 or 28,wherein the self-adhering membrane comprises a mineral surfaced area anda plurality of non-mineral surfaced areas forming selvage strips. 40.The method of claim 39, wherein the membrane comprises a modifiedbitumen, a SBS modified bitumen, or an APP modified bitumen.
 41. Themethod of claim 40, wherein the selvage strips are formed transverselyalong the membrane.
 42. The method of claim 41, wherein the selvagestrips are formed longitudinally along the membrane.
 43. A combined basesheet and insulating layer for a roof, comprising: a laminate includinga metal layer, and at least one plastic layer attached to an insulatingboard such that at least two sides of the laminate overhang two sides ofthe insulating board.
 44. The base sheet of claim 43, wherein said atleast one platic layer is made of a spun bonded plastic.
 45. The basesheet of claim 43, wherein said at least one plastic layer is made ofpolyester, polypropylene, polyethylene or a spun bonded olefin.
 46. Thebase sheet of claim 1, wherein the metal of said metal layer isaluminum.
 47. A method of forming a roof on a root deck comprising:providing a plurality of insulating boards having respective laminatesof a metal layer and at least one plastic layer attached to the boards,each laminate having at least two overhanging sides; and placing theplurality of insulating board on the roof deck such that each overhangof a laminate overlaps a side of another insulating board.
 48. Themethod of claim 47, further comprising adhering a self-adhering membraneto the laminate.
 49. The method of claim 48, wherein the laminate isplaced on the insulating board such that the metal layer faces theinsulating board and wherein the self-adhering membrane is adhered tothe plastic layer.
 50. The method of claim 48, wherein the laminate isplaced on the insulating board such that the plastic layer faces theinsulating board and wherein the self-adhering membrane is adhered tothe metal layer.